1. Field of the Invention
The present invention relates to a Group III nitride compound semiconductor light-emitting element and particularly to a flip chip type Group III nitride compound semiconductor light-emitting element.
2. Description of the Related Art
FIG. 6 shows a flip chip type light-emitting element 100 having a related-art configuration. The light-emitting element 100 includes a support 101, and a plurality of Group III nitride compound semiconductor layers 102 laminated on the substrate 101. The light-emitting element 100 has a surface in which electrodes 103 and 104 are formed and which serves as a mount surface. The light-emitting element 100 is mounted on a support 105 through the mount surface when light-emitting element 100 is used. In the light-emitting element 100 configured as described above, a surface 106 of the substrate 101 serves as a light-emitting surface.
In the light-emitting element 100, light emitted from a light-emitting layer-containing layer 107 is radiated out through a multilayer crystalline film constituted by a plurality of semiconductor layers. That is, light repeatedly refracted in interfaces between layers in the multilayer crystalline film is radiated out. Particularly, light emitted from the light-emitting layer-containing layer 107 toward the electrode 103 once reaches the electrode 103 and is reflected on a surface of the electrode 103 so that the reflected light travels toward the substrate 101 and passes through the multilayer crystalline film again. Accordingly, the light is repeatedly refracted by a larger number of times before radiated out. Because light repeatedly refracted in the multilayer crystalline film in such a manner is emitted from the light-emitting surface 106, the form of light radiation is largely affected by the thicknesses of the respective layers constituting the multilayer crystalline film and the states of the interfaces between the respective layers. That is, the characteristic of the light-emitting element largely depends on the thicknesses of the respective semiconductor layers and the states of interfaces between respective semiconductor layers. It is, however, difficult to control the thicknesses of the respective layers in the multilayer crystalline film strictly. Hence, there has been a problem that the characteristic varies from one light-emitting element to another light-emitting element. Moreover, variation in the characteristic of the light-emitting element directly results in variation in the characteristic of an LED lamp obtained by packaging the light-emitting element. Hence, it has been difficult to produce such an LED lamp having desired characteristic with a good yield.
Under such circumstances, an object of the invention is to reduce variation in the characteristic of a Group III nitride compound semiconductor light-emitting element.